package atomlist;

import java.util.Random;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.DelayQueue;
import java.util.concurrent.Delayed;
import java.util.concurrent.TimeUnit;

/**
 * @功能
 * @创建时间 2019/12/25
 * 可以用来做定时任务
 */
public class T07_DelayQueue {
    static BlockingQueue<MyTask> task = new DelayQueue<>(); // 无界队列，每个元素装建好之后都要等待一段时间才能被拿
    static Random r = new Random();
    static class MyTask implements Delayed{
    long runningTime;
    MyTask(long rt){
        this.runningTime = rt;
    }
        @Override
        public long getDelay(TimeUnit unit) {
            return unit.convert(runningTime - System.currentTimeMillis(),TimeUnit.MILLISECONDS);
        }

        @Override
        public int compareTo(Delayed o) {
        if(this.getDelay(TimeUnit.MILLISECONDS)<o.getDelay(TimeUnit.MILLISECONDS))
            return -1;
        else if(this.getDelay(TimeUnit.MILLISECONDS)>o.getDelay(TimeUnit.MILLISECONDS))
            return 1;
        else
            return 0;
        }
        @Override
        public String toString(){
        return ""+runningTime;
        }
    }

    public static void main(String[] args) throws InterruptedException {
        long now = System.currentTimeMillis();
        MyTask t1 = new MyTask(now + 1000);  //执行时间
        MyTask t2 = new MyTask(now + 2000);
        MyTask t3 = new MyTask(now + 1500);
        MyTask t4 = new MyTask(now + 2500);
        MyTask t5 = new MyTask(now + 500);
        task.put(t1);
        task.put(t2);
        task.put(t3);
        task.put(t4);
        task.put(t5);
        System.out.println(task);
        for(int i=0;i<5;i++){
            System.out.println(task.take());
        }
    }
}
